Sole for ski boot

ABSTRACT

The present invention relates to an outer sole ( 6 ) for a ski boot. The outer sole comprises a fastening pin ( 2 ) to attach a ski boot to a binding, two longitudinal and parallel outer sole ridges ( 7 ) which between them form a longitudinal recess ( 8 ), where the fastening pin ( 2 ) is arranged in and between the two longitudinal and parallel outer sole ridges ( 7 ). The outer sole may have two longitudinal and parallel outer sole ridges ( 7 ) that are comprised a number of fastening points which form at least two different positions ( 3; 4; 5 ) in longitudinal or vertical direction, the fastening pin ( 2 ) being arranged to be movable between the at least two different positions ( 3; 4; 5 ) in longitudinal or vertical direction.

The present invention relates to a ski boot arranged for releasable attachment to a ski by means of a ski binding. The ski boot comprises an outer sole, an upper part and an attachment member, the attachment member being arranged to match and cooperate with a locking mechanism on the ski binding.

During the practice of different forms of skiing, in particular the types of skiing in which the equipment that is used is particularly suitable for walking or running on skis, the front part of the ski boot is attached to the ski by means of a ski binding, as the ski binding and the ski boot are arranged to interact in such way that the heel can be lifted from the ski. This could either be achieved by the tip of the ski boot being attached or strapped by means of for example a traditional 75 mm ski binding or similar bindings, where a clamp holds the tip of the ski boot and keeps it fixated in such a way that the tip of the ski boot is kept more or less completely fixed relative to the ski to which it is attached, as the heel can be lifted from the ski by the ski boot being bendable. Most ski boots and bindings worked like this until the 80s when an attachment member was introduced in form of a steel pin on the front part of the ski boot, the said steel pin fitting into a groove in a ski binding, where the ski binding further fixedly clamped the steel pin and allowed some rotation around the attachment point constituted by the steel pin. Even if the heel of the ski boot now could be lifted in that the ski boot to some degree could rotate around the attachment point constituted by the steel pin, the ski boot was still bendable enough so that the bendability of the ski boot still to a large degree contributed to that the heel lifted from the ski.

It will be understood by those skilled in the art that the skiing experience to a large degree is affected by where and how the ski boot is attached to a ski by a ski binding. The skiing experience is also affected to a large degree by parameters such as the bendability of the ski boot, torsion stiffness and ability to support the foot. Depending on the skiing discipline that will be practiced, for example skating, classic, touring, light telemark etc., the requirements as to where and how the ski boot is attached to the ski, the bendability of the ski boot, torsion stiffness and ability to support the foot, will vary in such a degree that optimized special equipment has been developed for each discipline. In particular within the skating discipline, the development has gone towards significantly stiffer boots than earlier, not only stiffer in terms of torsion, but also in the transversal and longitudinal direction. This contributes to that the ski binding has taken over many of the bending qualities which the ski boot previously had, as the newest ski bindings are supplied with custom-adjusted spring members which are active in both rotational directions around the attachment point of the ski boot, in addition to that they are progressive with a custom-adjusted spring and power profile. These profiles can also be adapted to many needs, such as the practitioner's weight, strength and preferences, in addition to snow conditions, profile of the course etc. In this area there is a continuous development.

One of the possibilities that, as it has been realized, can be utilized to a higher degree than earlier is the integration of a type of “gearing” into the ski boot. Depending on where and how the ski boot is attached to a ski by means of a ski binding, the principle of leverage could be utilized to achieve a higher or lower gearing. In principle, conventional ski boots could be said to have a neutral gearing in which the rotational point and the rotational movement of the ski boot relative to the ski is selected based on what is considered as optimal in terms of biomechanics. If the rotational point is moved forwards or backwards (relative to the longitudinal direction of the ski boot), a higher or lower gearing could be achieved accordingly.

A higher gearing could be advantageous in a course which is relatively flat and/or under particularly quick snow conditions. It could become harder to keep the same frequency relative to a neutral gearing, but the developed power and the gliding length for each kick could become considerably larger, resulting in a considerably higher speed. The top speed could also become higher.

A lower gearing could be beneficial in a course which is relatively hilly and/or under particularly slow and heavy snow conditions. It could become easier to keep the same or higher frequency relative to a neutral gearing, and the developed power and the gliding length for each kick could become smaller, however it would be considerably easier to maintain the technique in steep terrain, and at the same time be able to accelerate faster when the terrain flattens out over hilltops. The top speed could become lower, but this will be of minor importance in a course which is relatively hilly and/or under slow and heavy snow conditions.

Other factors than profile of the course and snow conditions could also play a role in the choice of whether one wants higher or lower gearing. For an experienced practitioner individual differences with regard to body weight, strength and preferred frequency will contribute to whether the practitioner wants higher or lower gearing. For a beginner or someone who is in a poor physical condition and/or relatively heavy, a lighter gear can make it easier to walk, such that the skiing experience becomes better and the threshold for exercising lower.

Individual biomechanical and proportional differences between individuals may also result in different preferences. Such differences can for example be flexibility in the ankle joint, foot length, strength in calves, strength in legs, strength in upper body, the balance ability, individual technique etc.

EP2465371A1 relates to a solution in which two steel pins are releasably mounted on the front part of a ski boot by means of a fixture which for instance can be fastened with screws in the outer sole of the ski boot. The purpose of this is primarily that the steel pins, which are subject to wear and tear, may be easily replaced. EP2465371A1 also mentions that the position of the steel pins in longitudinal direction may be adapted based on the user's preferences, without discussing these preferences to any certain degree. According to EP2465371A1 the steel pins have been asymmetrically mounted on the fixture, as turning of the fixture will move the steel pins forwards or backwards, respectively. Alternatively, or in addition, the fixture may be slid backwards or forwards, as the fixture is mounted on the outer sole by screws. The outer sole comprises a number of screw holes, and depending on which holes that are used, the fixture could together with the steel pins be moved forwards or backwards. The fixture forms in itself a part of the walking surface.

The above potential for improving the utilization of power and/or the skiing experience is still at an early stage and has only recently become possible to exploit by the development of new types of ski boots and bindings.

The above potential is achieved and issues are solved according to the present invention by a device according to the appended independent claim 1. Further advantageous features and embodiments are set forth in the dependent claims.

FIG. 1 shows a perspective view of an embodiment of the present invention,

FIG. 2 shows an exploded view with details of an embodiment of the present invention,

FIGS. 3 a and 3 b show a top face and bottom face plan view of an embodiment of the present invention,

FIG. 4 a shows a cross-section of an outer sole according to an embodiment of the present invention along the section indicated as A-A in FIG. 3 a, and

FIG. 4 b shows a cross-section of an outer sole according to an embodiment of the present invention along the section indicated as B-B in FIG. 4 a,

FIG. 1 shows an outer sole 6 of a ski boot, where a fastening pin 2 can assume three different positions 3; 4; 5 in longitudinal direction, where the positions are selected from the group comprising a neutral position 4 with a neutral gearing, one or more positions 3 with heavier gearing, and/or one or more positions 5 with lighter gearing. FIG. 1 shows the fastening pin 2 arranged in the heaviest position.

According to the present invention, a ski boot 1 is further provided 1 with an outer sole 6 comprising two longitudinal and parallel outer sole ridges 7 which between them form a longitudinal recess 8. Each of the longitudinal and parallel outer sole ridges 7 have been arranged with a number of fastening points which define and correspond with the different positions 3; 4; 5 which the fastening pin 2 can assume.

According to the invention, the fastening points can be selected from the group comprising holes, grooves, recesses and pins.

According to the invention the fastening points can be arranged in pairs transversal to the longitudinal direction of the outer sole 6 in the above longitudinal and parallel outer sole ridges 7.

FIG. 2 shows a view of an outer sole 6 corresponding to the one shown in FIG. 1, but from a different perspective and with fastening pin 2 and two fixtures 8 shown in an expanded condition. According to the embodiment shown in FIG. 2, two fixtures 8 are provided which may be arranged in separate grooves 9 in each of the outer sole ridges 7 from the inside of the outer sole 7. According to this embodiment, the fixtures 8 are arranged prior to the mounting of the middle sole and upper part of the ski boot, such that the fixtures 8 are hard mounted when the ski boot is finalized.

Other embodiments could also be contemplated, for example an embodiment in which the outer sole ridges 7 comprise grooves wherein the fixtures 8 may be introduced from the outside of the outer sole 6, for example in grooves that are arranged on the bottom side or front side (not shown) of the outer sole back 7. Regardless of how or wherefrom the fixtures 7 are arranged, the fixtures 7, according to these embodiments of the present invention, will be locked when the fastening pin 2 has been mounted in one of the hole pairs 3; 4; 5. Alternatively, the fixtures 7 may be molded onto the outer sole 6, each in its separate outer sole back 7, such that the fastening pin 2 is not required to secure that the fixtures 7 are held in place.

The fastening pin 2 shown in FIG. 2 comprises threads and may further comprise a gasket, for example of the Nyloc™ type, forming a check nut effect. Alternatively, the fixtures may comprise threads that are completely or partly coated with a Nyloc™ type material, thus to achieve a check nut effect. Other locking methods could also be used, for instance glue (Loctite™ or other types of glue), or press fit, where the pin is pressed in such that it stays, and is knocked out again with a suitable tool.

The fastening pin 2 shown in FIG. 2 comprises a head of the umbraco type, whereas other screw grooves/heads (straight, cross, Torx or similar) may also be used within the scope and spirit of the invention. According to one embodiment of the invention, the one end of the fastening pin 2 comprises a groove which matches the hole 3; 4; 5 in which it should be introduced, whereas the other end comprises threads and the above screw head. Other variants may just as well be used, for example threads in the end farthest from the head, while a Nyloc™ type gasket is arranged around the end closest to the head etc.

Other methods for securing the fastening pin 2 may also be used. FIG. 3 a shows the outer sole seen directly from above (from the inside), groove 9 being shown into which the fixtures 8 easily can be introduced prior to the mounting of middle sole and upper part. As previously mentioned, fixtures 8 may also be molded into the outer sole 6.

FIG. 3 b shows the outer sole seen directly from below (from the outside), the fastening pin 2 being arranged in the hole pair 3, i.e. in the heaviest position. Depending on what one prefers, hole pair 3 may provide a gearing which is heavier than neutral, whereas hole pair 4 provides a neutral gearing and the hole pair 5 provides a lighter gearing. Alternatively, position 3 may be neutral, whereas positions 4 and 5 provide two lighter gearings, or 3 and 4 are heavier than the neutral position 5, etc. In most cases, one would select a configuration and location for the positions/hole pairs 3; 4; 5 where the middle one is neutral, and one accordingly has a heavier and lighter one on each side, however other configurations and placements are as mentioned possible.

FIG. 4 a shows the section A-A indicated in FIG. 3 a. The angles and distances that are indicated are relevant for the established NNN® standard from Rottefella®. It is understood that these are not limiting to the scope and spirit of the invention, as other standards (current or future) could require other angles and distances. With respect to the distance between the positions/hole pairs 3; 4; 5, a greater distance will imply a larger difference between the gearings and vice versa.

FIG. 4 a shows the section B-B indicated in FIG. 4 a. The indicated distance between the outer sole ridges 7 is relevant for the established NNN® standard from Rottefella®. It is understood that this is not limiting to the scope and spirit of the invention, as other standards (current or future) could require other distances. In FIG. 4 b the fixtures 8, fastening pin 2 and outer sole ridges 7 are cut-away.

In this text the attachment point of the ski boot to a binding (not shown) has been called a fastening pin 2. A steel material is most commonly used for such attachment points. Steel is a ductile, strong and durable material which therefore constitutes an excellent choice for such attachment points. It should be understood that other materials, metals and alloys may also be used. A relevant and alternative metal is titanium, which is preferred by some due to its light weight. Titanium is however worn considerably faster than the relevant steel alloys, and are at the same time more prone to breakage due to its brittleness. One could also contemplate pins of carbon, ceramic materials, other metals/alloys, or combinations thereof.

If one exploits the advantages of the present invention, i.e. provides ski boot and binding systems which offer the opportunity to select and vary the gearing, this could have consequences for other aspects of the ski boot and binding system. If one is to exploit the advantages of a heavier gearing, it could be an advantage to provide a ski boot which is significantly stiffer, in particular in the front or foremost part, compared with today's conventional boots.

It could also become necessary to adapt the choice and design of the flexor(s) in the binding. Since the contact face(s) 10, 11 in front and/or underneath the front part of the boot will move relative to the flexors and their contact faces with the ski boot, the flexor in the binding may have to be made thicker or thinner depending on which position one selects.

In addition, one can select a flexor softness/stiffness adapted to the gearing that one selects. If one selects a heavier gearing, it could for example be advantageous with a stiffer flexor, whereas for a lighter gearing one could prefer a softer flexor. The walking or running frequency could also be of importance as to which flexor softness/stiffness and what flexor-response one selects. One can for instance contemplate that at a lighter gearing (higher frequency) a flexor with a fast response could be preferred, such that the ski quickly returns to its initial position after each stroke or kick. In the opposite case, one can for instance contemplate that at a heavier gearing (lower frequency) a flexor with a slower response could be preferred, such that the ski does not return too quickly to its initial position after each stroke or kick.

When this description uses the term “neutral position”, it refers in principle to the position in which one according to the NNN standard has positioned conventional fastening pins or steel pins. This position is per se not exact since it to a large degree is based on extensive testing and experimenting. What could be called a neutral position will to some extent vary based on which standard that is used and a large number of parameters, such as sole thickness, sole stiffness, general boot construction, boot and sole materials, binding system, flexor stiffness, flexor qualities (for example bending stiffness versus rotational angle around the attachment point of the ski boot), etc. Even if the term “neutral position” may seem somewhat vague, it turns out that most ski boot manufacturers have located the fastening member in what by the skier would be perceived as the neutral position.

In addition to the number of holes that form at least two different positions 3; 4; 5 in longitudinal direction, where the fastening pin 2 is arranged to be movable between the at least two different positions 3; 4; 5 in longitudinal direction, one can according to another aspect of the invention provide holes which form at least two different positions 3; 4; 5 in vertical direction, the ski boot being able to be lifted in vertical direction in addition to, or optionally instead of, being able to be repositioned in the longitudinal direction. It has been found that one can improve the skiing experience, power consumption and balance under some snow conditions by lifting up the front of the ski boot relative to the heel. Wedge-shaped spacers which are arranged between the binding and ski are used to achieve this. Another way to achieve a similar effect could be to move the fastening pin farther from the bottom side of the ski boot. In addition to such an effect, which in reality relates to a another aspect, the net effect of moving the fastening pin in vertical direction could correspond to or strengthen the effect of moving the fastening pin in longitudinal direction. Moving the fastening pin somewhat down could for example correspond to moving the fastening pin somewhat backwards etc. 

1. An outer sole for a ski boot comprising: a fastening pin to attach a ski boot to a binding, two longitudinal and parallel outer sole ridges which between them form a longitudinal recess, where the fastening pin is arranged in and between the two longitudinal and parallel outer sole ridges, wherein in the two longitudinal and parallel outer sole ridges comprise a number of fastening points which form at least two different positions in longitudinal or vertical direction, the fastening pin being arranged to be movable between the at least two different positions in longitudinal or vertical direction.
 2. The outer sole according to claim 1, where the fastening points are selected from the group comprising holes, grooves, recesses and pins.
 3. The outer sole according to claim 1, where the at least two different positions in longitudinal or vertical direction are selected from the group comprising a neutral position with a neutral gearing, one or more positions with heavier gearing relative to a neutral gearing, and one or more positions with lighter gearing relative to a neutral gearing.
 4. The outer sole according to claim 1, where the fastening points which define and correspond with the different positions are arranged in pairs transversal to the longitudinal direction of the outer sole in the above longitudinal and parallel outer sole ridges.
 5. The outer sole according to claim 1, where fixtures are arranged in separate grooves in each of the outer sole ridges, the fixtures comprising a number of fastening points which define and correspond with the different positions which a fastening pin can assume.
 6. The outer sole according to claim 1, where the fastening pin comprises a threaded part, a screw head and a gasket which give a check nut effect.
 7. The outer sole according to claim 1, where the fastening pin is attached by press fit in respective positions.
 8. A fastening pin to attach a ski boot to a binding, wherein it is arranged to be movable between at least two different positions in longitudinal or vertical direction in an outer sole of a ski boot.
 9. The fastening pin according to claim 8, comprising a threaded part, a screw head and a gasket which give a check nut effect.
 10. The fastening pin according to claim 8, being arranged for press fit in the respective positions.
 11. A binding system to attach a ski boot to a ski, wherein the ski boot has an outer sole comprising a fastening pin to attach the ski boot to a binding, and two longitudinal and parallel outer sole ridges which between them form a longitudinal recess, where the fastening pin is arranged in and between the two longitudinal and parallel outer sole ridges, comprising a number of fastening points which form at least two different positions in longitudinal or vertical direction, the fastening pin being arranged to be movable between the at least two different positions in longitudinal or vertical direction, the binding further comprising at least one flexor adapted to the position the fastening pin assumes. 